Different concepts and combinations have been used to enhance jewelry. Where small diamonds are involved, it is common to set them in a large metal setting having colors or designs that tend to cause the diamond or other precious stone to appear larger. In other instances, semiprecious stones of relatively large size have contrasting precious stones of relatively smaller size mounted thereon or associated therewith. The contrast may be not only in size, cut and shape, but also in kind and/or color.
U.S. Pat. No. 5,090,216 discloses enhancing a large man-made gemstone such as a zirconia by bonding thereto a precious gemstone such as a diamond. The diamond is selected with a girdle diameter that is slightly less than the width of the crown table of the cubic zirconia. The cubic zirconia has a conical seat ground in its table to match the angle of the diamond pavilion. The conical seat is ground deep enough so that the diamond girdle is just below the crown table surface of the cubic zirconia. The diamond is then glued or cemented into the conical seat with enough glue to slightly cover the crown girdle facets of the diamond.
In the present application and claims the term ‘color’ will be used in association with naturally or artificially colored diamonds with distinct, attractive tints, and particularly with diamonds having fancy colors, where the grade and value of diamonds increase with color intensity. Among colored diamonds, diamonds with very low transparency (from nearly semitransparent to opaque) are known as ‘dark diamonds’. These are considered not to return light and are normally dark gray, very dark green or truly black.
The above use of the term “color” should be distinguished from a very special use of this term in the diamond industry with respect to diamonds returning light (hereinafter ‘light color’ diamonds), where diamonds are graded by how closely they approach colorless so that a diamond being said to have ‘fine color’, frequently has no visible color at all. In such ‘light’ diamonds, the amount of light returned to the eye from a light cut diamond, depends on how well the diamond in question reflects and refracts light including dispersed rays of different wavelengths, which are reflected from the internal surfaces of the diamond.